Relief device for hot-water heaters



H. U. FULLER. RELIEF DEVICE FOR HOT WATER HEATERS.

APPLICATION FILED MAR. 19. 1921.

1,438, 1 O5 Patented Dec. 5, 1922.

Fatcnted Dec. 5, 1922.

UNETE STATES HARRY U. FULLER, OF PORTLAN D, MAINE.

RELIEF DEVICE FOR HOT-WATER HEATERS.

Application filed- March 19, 1921.

To all whom it may concern Be it known that I, HARRY U. FULLER, a citizen of the United States, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Relief Devices for Hotater Heaters, of which the following is a specification.

My invention relates to a safety device for hot water systems where water meters are used, containing mechanism which is spoiled or injured by hot water.

In the ordinary hot water system when the openings were all closed and when the boiler was supplied directly from the street main the house supply pipe was open or unobstructed. Under these conditions, the water in the boiler as it expanded was pushed back toward the water main against the street pressure and no harm resulted since any undue pressure on the boiler was thereby relieved. Vihen water meters came to be adopted and located in the house supply ipe inside the house wall, it was found that hot water from the boiler was sometimes forced back through the supply pipe toward the main and entering the meter it damaged some of the parts which were made of hard rubber, sometimes ruining the meter.

To offset this difficulty and to guard against injuring the meters, the practice was adopted of placing a check valve between the meter and the hot water tank to prevent hot water from entering. The use of the check valve, however, sealed the system and made it dangerous so that a relief valve was placed on the pipe inside the check valve for the purpose of making it safe.

The use of check valves and relief valves has not proved safe and many explosions of hot water boilers have been attributed to the fact that the relief valve did not Work when required and the bursting of the boiler was the result. a

I overcome this difficulty and make these systems perfectly safe by placing between the meter and the boiler an elongated chamber connecting at each end with the supply pipe so that as the hot water is forced in from the boiler at one end, it will displace the cold water in the chamber causing it to work back through the meter toward the main.

The capacity of the. chamber is substan- Serial No. 453,609.

tially as great as the amount the water inthe tank will expand when heated to itshighest ing the usual arrangement of the supply pipe boiler and meter.

In the drawing, 1 is the boiler which maybe connected with a gas heater 2 or with a kitchen range. The supply pipe 3 for the boiler comes in through the cellar wall of the house and just inside the wall is located the water meter 4:. At some point in the supply pipe 3 between the meter and the boiler I locate an elongated closed tank or chamber 5 connected at each end with the supply pipe. Thus, the water driven back from the boiler by the expansion of water in the closed system works back to the cham ber 5 flowing in at one end and out through the other. The chamber is preferably placed in an upright position so that the hot water enters the top and the cold water flows out through the bottom but no hot water can flow through it to enter the meter because its capacity is more than enough to take care of what expansion can possibly take place.

in the boiler when it is heated to. its highest point. As the hot water enters the chamber 5 the heat rapidly radiates and the water gradually cools, thus diminishing the danger of flooding the meter with hot Water.

As a matter of practice, I make this chamber of 4: in. pipe about 18 in. long with a cap on each end and holding approximately one gallon and I find that this is suflicient in all ordinary cases.

The simplicity of my device, its absolute safety as a substitute for the check and relief valves makes an effective solution of the whole difiiculty.

I claim 1. In a hot water system, the combination with a hot water boiler, of an unobstructed supply pipe connecting said boiler to the water main, a water meter in said supply pipe, and an elongated closed chamber in said supply pipe between the meter and boiler and connected with said supply pipe at opposite ends and of capacity substantial- 1y equal to the amount of expansion by Volume of the boiler Water from its minimum to its maximum temperatures.

2. In a hot Water system, the combination with a hot Water boiler, of an unobstructed supply pipe therefor connected with the main supply and a Water meter in said supply pipe, an enlarged chamber in said supply pipe between the boiler and the meter, said chamber being of suffieient capacity to hold a quantity of Water substantially equal to the amount of expansion by Volume of the boiler Water from its minimum to its maximum temperatures.

HARRY U. FULLER, 

